Because you can never really have too many external memory SDHC cards, Staples has put two popular class 10 SanDisk models on sale for a limited time. Right now you can pick up the SanDisk 16GB Ultra SDHC (Class 10) for $19.94 and the SanDisk 32GB Ultra SDHC (Class 10) for $34.94. Quantities are limited so you'll definitely want to place an order or head to your nearest Staples before stock runs out.
Digital photographers will find some value here as you can never have enough memory cards to go around. Higher end digital SLRs and point-and-shoots that shoot in full HD will need a card with class 10 speeds to be able to record without any hiccups. Normally, you're looking to pay about $40 for the 16GB model and $80 for the 32GB variant so this is a good time to pick a card or two if you're in need.
Both cards are on sale now but only until July 22. Staples offers free shipping on orders over $50.